Electric heating appliances



Sept. 25, 1956 K. H. WALKOE ELECTRIC HEATING APPLIANCES 3 Sheets-Sheet 1 Filed July 2l, 1955 INVENTOR. Kenne/h H Wal/roe Sept. 25, 1956 K. H. wALKoE ELECTRIC HEATING APPLIANCES :s sheds-sheet 2 Filed July 2l, 1955 FIG. 3

FIG. 5

i90/L 60M TE MR INVENTOR. Kenner/7 H Wol/foe Sept. 25, 1956 K. H. wALKoE ELECTRIC HEATING APPLIANCES 5 Sheets-Sheet 3 Filed July 2l, 19.55

INVENTOR. lKennel/1 H. Wa//roe @dung United States Patent O 2,764,565, ELEc'rRle'nnAtrINo: APPLIANCES Kenneth. H. VValkoe,l Lombard., lll., assignor to General Electric Companhacorporation of New York Application JulyZlg` 1955, Serial No. 523,472? 10. claims. (omis- 37) surface-unit` cooking. appliance and comprising. a, heatingunit selectively movable between a, deep-well. cooking position and a` surface-unitl position, and.A incorporating a temperaturesensiug unitthatis. operative to sense the.

temperature of a; cooking.' vessel supportedh thereby in either cookingI position. thereof, which temperature sensing unit. is employed. to control,V upon a. temperature basis, selectiveheatingof theheating unit.

Another object of theY invention is to provide in4 an automatic cooking systemofthe. character noted, a manually operable controller that is, selectively operative to establish. either the.. automatic. temperature-controlled cooking operation. governed. by the. temperature. sensing unit or any one3 of, anilmber offixed` electrical heating connections. to. theY heating. unit,` which. xed heating.

connections are independent of the temperature. sensing unitwher.eby, the cooking operations. that are carried out in the combination, cooking appliance may proceed in either cooking position thereof and upon either. a basis of automatic.-temperaturecontrolor abasis, of xed. heating rates.

A further objectofthefinyention.is to. provide a combination cooking, appliance of. the character described, that is of. improvedtconstruction and arrangementso that. boththe electric. power. supply connections and the. con` trol. connectionsare,entirely. safe. and of long life, notwithstanding the. fundamental. movements of the heating unitbetween its respective cooking positions and the additional, movementsi of.. the. temperature. sensingl unit with respect tothe. heating unit as required in the. use of different cooking vessels supported by the heating unit.

Astill further objectof the. invention is to provide a combination cooking. appliance. of the character noted that is of. improved.. and. simplified construction and arrangement..

Further features of the, invention pertain to the particular arrangement. of. the elements. of the. automatic cooking system andof the c ombination cooking. appliance incorporated therein..

The invention,. both as to its organization and method of operation, together. with further objects and advantages thereof, will. best be understood by reference to the following specification takenv in. connection with the accompanying drawings, in` which:

Figurel is a fragmentaryv front perspective view of the upper. portionv of anelectric range incorporating an automatic cooking; system and including a combination 2. deep-well and surface-unit cooking appliance and embodying the present invention;

Fig. 2v is` anenlarged side elevational view. of the; combination. cooking appliance, illustratingl in. vertical section the receptacle. thereof. supporting the heating unitV thereof inl its. deep-well position;

Fig.. 3 is another enlarged. side elevational. view, simi-- lar to Fig. 2, of the. combinationv cooking appliance; il.-` lustrating in vertical section the receptacle supporting, the heating unitin. its; surface-unit. position, this view being. taken in, the. direction, ofthe arrows along the. line. 3 3. in. Fig.. 2;

Fig, 4 is an enlarged plan view of theV combination cooking appliance, illustrating the tilted` or transition position. of the heating unit,I that is required in: order. to. effect movement thereof into or out. of its. surfacerunit pcf sition, this transition. position of theheating unit also: being indicated. in. broken. linesin Fig. 2;

Fig. 5 is. an electricalydiagram. of the. automatic. cooking. system that isincorporatedin the electric range of Fig.. 1, and, including the combination. cooking; appliance. of Figs.. 2.to. 4, inclusive; and,

Fig. 6. isA a. greatly. enlargedfragmentary, vertical sectional, view. of the heating; Unit, taken: in the. direction: of. thearrows along the line 6 6 inFig. 4.

Referring now to Fig, 1 of thev drawings,y there. is. il.-` lustrated. an. electric range, 10 incorporating. anl automatic cooking., system. including a combination deep-well and, surfacefunit cooking appliance and embodying.. the fea.- tures of the present invention. The range. 10.v comprises. an upstanding body. 11 provided with. a. substantiallyhorizontally disposed. cookingg top 12. supporting.y a plurality of. surfacefunits or hotplate, 13., 15 and-16,` an'd the combinationv cooking` appliance, 14, the.,elements.13

14,. 15` and. 16, being arranged. in. spacedfapart relation. in asubstantia-lly. rectangular pattern on, the left-hand` sideo the cooking..V top.12. Thebody 1l alsohouses an, oven, not shownt. in. the right-hand portion thereon. and.

a Compartment, not shown,A inf the left-hand portion.

thereof, the. oven and the compartment being; provided with respective.: front doors, not! shown. The cookingY top 12, carries, an.' upstanding, backsplash 1,'7`adjacent to. the rear thereof that, in. turncarries.a plurality of surfaceheating unit selector switches 18,20 and 21', a specialselector or. control. switch 19, a rstpushbutton temperature controller 19A, 'a second rotary temperature controller 19B,. anl oven selector switchv 22, and an oven regulator or thermostatic switch 23.; the elements namedbeing arrange-d generally in a row across the front of the. backsplash 17;' The selector switches 18', 2li and 21 respectively correspond to the surface heating units 13, 15, and 16,. and. are of conventional construction and. are respectively included in the electric heating circuits thereof; while the special control switch. 19' corresponds. to-the combination cooking. appliance 14 of special construction andis includediin the electric heating, circuit. ofv the heating unit thereof; Each ofthe surface. heating. unit selector switches 18, 20" and' 21 is of the pushbutton type and is preferably ofthe constructiont of than disclosed in U. S; Patent No.. 2,431,904', granted on December 2, 1947, to John IL. Andrews; the special, control. switch 19 is of. the pushbutton type, and isy of a, modiedl form. with respect. to the construction disclosed inthe Andrews. patentmentioned,y as explained more.v fully hereinafter; the. pushbutton `switch 22. is of the pushbutton-.typeandtis substantially of theoonstruction` disclosed'in.v therAndrews patent; the pushbuttontemperature controller 19A'.y isy ofthe pushbutton type and is of`- aV modifiedA form\ with respect, toy the construction disclosedlimthe Andrews patent, as` explained more fully hereinafter; the rotary controller 21Biis essentially of standard rotary construction; and the thermostatic switch 23 is of conventional construction.

The cooking top 12 has a plurality of openings therein that respectively receive the surface heating units 13, 15 and 16 and the combination cooking appliance 14. The surface heating unit 13, etc., may be fundamentally of the construction disclosed in U. S. Patent No. 2,563,443, granted on August 21, 1951, to Oliver G. Vogel and Francis E. Kirk; while the combination cooking appliance 14 is fundamentally of the construction disclosed in U. S. Patent No. 2,519,051, granted on August 15, 1950, to Francis E. Kirk.

Referring now more particularly to Figs. 2, 3 and 4, the combination cooking unit 14 comprises an upstanding generally cylindrical receptacle 24 terminating at the top thereof in an outwardly directed annular ange 25 and terminating at the bottom thereof in an inwardly directed bottom wall 26 having a centrally disposed drain opening 26 formed therein, the receptacle 24- being housed within the range body 11 and disposed below the corresponding left rear opening provided in the cooking top 12 and supported by the surrounding flange 25. Tlhe receptacle 24 is provided with an upper support 27 disposed inwardly with respect to the annular flange 25 and a lower support 28 disposed Somewhat above the bottom wall 26, and houses an electric heating unit 30 that is movable between a lower deep-well cooking position, as shown in Fig. 2, and an upper surface-unit cooking position, as shown in Fig. 3.

As illustrated in Fig. 6, the unit 30 comprises an open spider 31 including a centrally disposed annular ring 32 and a number of radially extending arms 33, as well as a surrounding supporting or trim ring 34 that is arranged directly to engage the upper and lower supports 27 land 28 carried by the receptacle 24, as explained more fully hereinafter. In turn, the spider 31 carries a heating element 35 including respective inner and outer sections 35a and 35h. The heating element 35 is generally in the form of a helical coil or spiral, the turns of which are arranged in radially spaced-apart relation; and preferably the heating element 35 is of the metal sheath-helical resistance conductor type disclised in U. S. Patent No. 1,367,341, granted on February l, 1921, to Charles C. Abbott. The top surfaces of the coils of the heating element 35 are flattened to define a substantially lhorizontal plane adapted to engage and to support the bottom wall of a cooking vessel, or the like, not shown. In the arrangement, the heating element 35 is disposed intermediate the central ring 32 and the outer ring 35, and the supporting platform thereof is positioned somewhat above the rings 32 and 34 so that the bottom wall of a supported cooking vessel engages only the coils of the heating element 35. The rear extremities of the inner and outer sections 35a and 35k of the heating element 35 extend downwardly f and rearwardly with respect to the spider 31 and carry electrical power terminals 36, the terminal ends of the heating element 35 being suitably supported by an arm 37 carried by the spider 31. Also, the outer en-d of the arm 37 carries a terminal box 38 housing the power terminals 36 and carrying a rearwardly projecting tube 39 that accommodates electrical connections to the exterior of the heating unit 30, as explained more fully hereinafter.

Also the heating unit 30 comprises a temperature sensing unit 40 that includes a substantially L-shaped tube 41 provided with a rearwardly extending arm 42 and an upwardly extending arm 43 positioned below and in alignment with the central opening through the inner ring 32, the extreme rear end of the arm 42 being carried by a xture 44, and the extreme top end of the arm 43 carrying a temperature sensing button 45. More particularly, the "nxture 44 is arranged below the inner end of the arm 37 and somewhat forwardly and below the terminal box 38 and is directly carried by a depending arm 46. The

upper end of the arm 46 and the inner end of the arm 37 are secured commonly to the adjacent rearwardly directed arm 33 of the spider 31 by rivets 47. Specifically, the lower end of the arm 46 terminates in a fixture 48 carrying an outwardly directed pivot pin 49 projecting through an opening provided in the upper portion of the fixture 44, whereby the xture 44 is pivotally mounted upon the pivot pin 49, a spiral spring 50 being arranged between the pivot pin 49 and an outwardly projecting tab 51 carried at the top of the fixture 44 and biasing the fixture 44 in the clockwise direction, as viewed in Fig. 6. Further, an outwardly projecting stop 52 is carried by the lixture 4S in overhanging relation with the adjacent portion of the rear arm 42 and forwardly of the pivot pin 49, whereby the tube 41 is biased in the clockwise direction by the spring 50 in order to move the temperature sensing button 45 into an upper position disposed somewhat above the plane of the heating element 35. In the operation of vthe heating unit 30, it will be understood that when a cooking vessel is placed upon the heating platform of the heating element 35, the bottom wall thereof engages the button 45 moving the same into a lower position, the tube 41 being pivoted downwardly in the countercloekwise direction, as viewed in Fig. 6, about the pivot pin 49 and against the bias of the spring 50. Of course, when the supported cooking vessel is subsequently removed from the heating platform of the heating element 35, the sensing button is returned into its upper position by the action of the spring 50, the upper position thereof being established by the cooperation between the stop 52 and the adjacent portion of the rear arm 42 of the tube 41.

The sensing button 45 is of substantially disk-like structure, the central portion thereof terminating in an outwardly and downwardly directed surrounding flange that is rigidly secured to an annular part 53 terminating in a lower downwardly directed substantially semi-spherical socket 54 directly carried by an upwardly directed substantially semi-spherical ball 55 provided on the extreme upper end of the arm 43 of the tube 41; whereby the parts 55-54 constitute a ball and socket joint accommodating universal movements of the sensing button 45 with respect to the extreme upper end of the arm 43 so as to insure good thermal contact between the sensing button 45 and the bottom wall of a cooking vessel supported by the heating platform of the heating element 35, and notwithstanding irregularities therein or the particular configuration thereof. Hence, it will be understood that when a cooking vessel is placed upon the heating platform of the heating element 35, the pivotal connection between the iixtures 44 and 43 accommodates the downward movement of the tube 41, and the ball and socket connection 55--54 accommodates the universal movements between the sensing button 45 and the upper end of the arm 43 of the tube 41. The sensing button 45 is hollow Iand houses a temperature sensing element S6 arranged in good heat exchange relation with the central portion thereof, the sensing element 56 being movable with the sensing button 45. Preferably, the sensing element 56 is formed of thermistor material having a high negative coefficient of resistance; thermistor material consists essentially of sintered aluminum oxide and an oxide of magnesium, manganese, titanium, iron, nickel, cobalt, Zinc, etc., and has a coefficient of resistance corresponding to a resistance rate of change of about: 0.044 ohm/ ohm/ C For example, the thermistor 56 may have a total resistance of 100,000 ohms at 25 C. and a total resistance of only 580 ohms at 200 C., the total resistance thereof changing very rapidly as the temperature thereof is elevated above the ambient temperature. The extreme outer end of the arm 42 carries control terminal structure 57 that is operatively connected to the thermistor by electrical wiring 58 extending therebetween and through the tube 41. For example, the electrical wiring 56 may be formed of silver and may be covered with an insulating material capable of withstanding the relatively high temperatures involved, such, for example, as polytetrailuoroethylene, -sold as Teflon Finally, the heating unit 33 comprises a downwardly extending drip pan 59 disposed below Athe spider 31 and secured in place by a number of spring clips 60 carried by the outer ring 34, the lower central portion of the drip pan 59 having a drain opening ,61 therein, and the upper rear portion of the drip pan 59 having a notch `62, therein. The drain opening 61 also accommodates the passage of the tube 41 therethrough and movement of the tube 41 without interference with the drip pan S9, while the notch 62 accommodates the passage therethrough of `the arms 37 and 46 as well as the rearward extensions of .the heating element 35. Thus it will be understood that the fixtures 44 and 48 and the associated parts are disposed below and exteriorly of the drip pan 59 rearwardly of the central opening 61, while the tube 4l projects ythrough the opening 61, the upper arm 43 thereof being disposed within the contines of the drip pan 59 and below the spider 31. This arrangement accommoda-tes ready placement .and removal of the drip pan 59 by virtue of the resiliency of the spring clips 60; and in passing, it is noted that the tube 41 may be moved downwardly about the pivot pin 49 through a considervafble angle in order to accommodate the ultimate disengagement of the drip pan 59 and the complete removal lthereof from the heating unit 30. Of course, the replacement of the drip pan 59 is eiected in a reverse manner; and in passing, it is noted that the drip pan 59 also serves -the reector function causing the downwardly directed heat from the heating unit 3S to be reflected back upwardly onto the bottom wall of the supported cooking vessel.

The heating unit 39 has a lower deep-well cooking `position illustrated in Fig. 2, wherein it is supported in place by -engagement of the outer ring 34 with the lower support 2S; and the heating unit 3i) has -an upper surface unit cooking position illustrated in Fig. 3, wherein it is supported in place by engagement of the outer ring 34 with the upper support 27; guided movement o'f t-he heating unit 30 between its respective cooking positions is laccommodated lby an vopstanding slot l63 formed in the receptacle 24 and receiving the tube 39 projecting rearwardly from the terminal housing 3S. Speciiically, the extreme rear end of the tube 39 carries an outwardly directed annular flange 64 that is somewhat larger -in diameter than the width of the major and upper vportion of :the slot 63, so as to prevent total disengagement of the heating unit 30 with respect to the receptacle 24; however, a connecting opening 65 is formed in the receptacle V24 and joining the extreme lower end of the slot 63 so as to accommodate the passage therethrough of the annular flange 64 land the consequent total disengagement of the heating unit 30 with respect to the receptacle 24.

As best shown in Fig. 4, the upper support 27 comprises respective front and rear sections so as to provide a pair of intermediate cutouts or notches 66 therethrough 'that are spaced laterally apart a distance somewhat greater 'than the diameter of the outer ring 34 so as to accommodate passage of the heating unit 30 in a tilted position into and out of its upper surface-unit position, as illustrated in Fig. 4 and as indicated by the broken lines in Fig. 2. Specifically, when the heating unit 30 is moved from its deep-well cooking position of Fig. 2 into its surface heating cooking position of Fig. 3, it is tilted upwardly in the general manner indicated in Fig. 2 so that the ring 34 may pass through the notches 66 provided Vin the upper support Z7 as the heating unit 30 is lifted therethrough; and subsequently the heating unit 30 is returned downwardly back into a stable and subsequently horizontal position so that the front and rear portions of the ring 34 respectively engage the front and rear portions of the upper support 27, whereby the heating unit 30 ,occupies its surface-unit cooking position shown in Fig. 3. Of course, it will be understood that the ret-urn of vthe heating unit 30 from its upper surface-unit cooking -position ,of Fig. 3 zback into its lower deep-well cooking position of Fig. 2 is accomplished in a reverse manner by tilting, as illustrated in Fig. 4, followed by lowering onto the lower support 28.

Finally, the combination appliance 14 comprises .an electric vcontrol -circuit diagrammatically illustrated in Fig. 5; which control circuit is preferably connected and arranged in the vmanner disclosed in the copending application of Robert J. Molyneaux, Serial No. 521,666, tiled July 13, 1955; which control `circuit comprises a 3-wire Edison source of power supply of 236-volts, single-phase, .60 cycles, A. C., the pushbutton switch 19, the -pushbutton controller 19A, the rotary controller 19B and a temperature ycontrol circuit, indicated generally at 70. More particularly, the range 10 comprises a terminal block 71 terminating the two outside conductors 72 and 73 and the grounded neutral :conductor 74 of the power source; which conductors are connected by ya supply cable y75 to the pushbutton switch 19. The pair of power terminals 36 respectively terminating the -oilset ends of the inner heating element section ,35a are connected to two vconductors 76 and 77; while the pair of power terminals 36 respectively terminating the offset ends of the outer heat-ing element section 35h are respectively connected to two vconductors 78 and 79; which conductors 76, 77, 78 land 79 comprise a power cable S0 extending from the heating unit 30 through the -tube 39 to the exterior of the combination appliance 14 and ultimately both to the pushbutton switch 19 and to the 4temperature control circuit 70, The pair of control terminals 57 terminating the electric wiring 5,8 extending to the respective terminals of the thermistor 56 are respectively connected lto two conductor-s 81 and 82 comprising a control cable 83 extending from the heating unit 30 through the tube 39 to the exterior and ultimately lto the temperature control circuit 70. In the arrangement, the power cable `and the control cable `83 `comprise tlexible cables so as to accommodate the movements of the heating unit 30 between its respective heating posit-ions. The 'pushbutton switch 19 is also connected -via a control cable 84 to the temperature control circuit 70; while the pushbutton Vcontroller 19A and the rotary controller -1-9B are respectively connected by two control cables I85 and S6 to the control circuit 70.

In the arrangement, the pushbutton switch 19 comprises six individual pushbuttons respectively designated: high, 2nd, 3rd, low, auto (abbreviation Vfor automatic) and om as well as interlock mechanism responsive to operation or depression of any one of the pushbuttons out of its normal position for returning the prior lastoperated one of the pushbuttons back into its normal projected position. The pushbutton controller 19A comprises four individual pushbuttons respectively designated: fry, high boil, low boil and xed temp, as well as interlock mechanism responsive to operation or depression of any one of the pushbuttons out of its normal position for returning the prior last-operated one of the pushbuttons back into its normal projected position. The rotary controller 19B comprises a manually rotatable dial 10' having low, medium and high positions in its continuous range of operation.

i Considering now the mode of `operation of the combmation appliance 14, it is pointed out that it is operated in a-n identical manner in each of its respective cooking positions and may be selectively controlled either to produce a series of iixed heating rates or to maintain a predetermined temperature of the bottom wall of a cooking vessel supported by the heating unit 30. Specically, when the off pushbutton of the pushbutton switch 19 occupies its operated position, the supply cable 75 is disconnected from the power `cable 80 and from the control cable 84; whereby the heating unit 35 is .deenergized and the control circuit 70 is rendered inactive. When the high, 2nd, 3rd and low .pushbuttons yof the pushbutton switch 19 are respectively operated, respective fixed electrical heating connections are established between the supply cable 8S and the power cable Sil and thus to the heating unit 3i) so as to effect heating thereof at the four respective fixed heating rates. More particularly, in the high position of the pushbutton switch i9, the inner and outer sections 35a and 351; are connected in parallel relation across the outside lines 72 and 73 of the power source to complete the high heating connection entirely independent of the temperature control circuit '76; in the 2nd position of the pushbutton switch lli-'2, the inner section 35a is connected across the outside lines 72 and 73 of the power source to complete the 2nd heating connection entirely independent of the temperature control circuit 7il; in the 3rd position of the pushbutton switch 19, the inner and outer sections 35a and 3517 are connected in parallel relation across the Outside line '72 and the neutral line 74 to complete the third heating connection entirely independent of the temperature control circuit 79; and in the low position of the pushbutton switch 19, the inner section 35a is connected across the outside line and the neutral line 74 of the power source to complete the low heating connection entirely independent of the temperature control circuit 70.

When the automatic pushbutton of the pushbutton switch 19 occupies its operated position, the supply cable 75 is connected to the control cable 84, whereby the temperature control circuit 70 is rendered active and the heating of the heating unit 3? is governed entirely by the temperature control unit 7f3 and based upon the temperature of the thermistor 56 and the adjusted positions of the pushbutton controller 19A and the rotary controller f9B, as explained more fully below.

First assuming that the fixed temperature pushbutton of the pushbutton controller 19A occupies its operated position, a resistance network, not shown, in the temperature control circuit 76 is set entirely by the pushbutton controller 19A and cooperates with the thermistor S6 to govern the temperature control circuit 70 so as to effect selective energization of the heating unit 3ft so that the bottom wall of the supported cooking vessel is maintained at a temperature in the approximate range 160 F.i5 F., the rotary controller 19B being disabled at this time.

Now assuming that the low boil pushbutton of the pushbutton controller 19A occupies its operated position, the resistance network, not shown, in the temperature control circuit 70 is set jointly by the pushbutton controller 19A and by the rotary controller 19B and cooperate with the thermistor 56 to govern the temperature control circuit 70 so as to effect selective energization of the heating unit 30 so Athat the bottom wall of the supported cooking vessel is maintained at a temperature in the approximate range 200 F.2l5 F., the rotary controller 19B being enabled and selectively operative to effect the F. modification of the temperature band within the low boil temperature range noted fundamentally established by the pushbutton controller fQA.

Next assuming that the high boil pushbutton of the pushbutton controller 19A occupies its operated position, a resistance network, not shown, in the temperature control circuit 70 is set jointly by the pushbutton controller 19A and by the rotary controller 19B and cooperate with the thermistor 56 to govern the temperature control circuit 70 so as to effect selective energization of the heating unit so that the bottom wall of the supported cooking vessel is maintained at a temperature in the approximate range 216 F.-230 F., the rotary controller 19B being enabled and selectively operative to effect the 20 F. modification of the temperature band within the high boil temperature range noted fundamentally established by the pushbutton controller 19A.

Finally assuming that the fry pushbutton of the pushbutton controller 19A occupies its operated position, the resistance network, not shown, in the temperature control circuit 70 is set jointly by the pushbutton controller 19A and the rotary controller 19B and cooperate with the thermistor 56 to govern the temperature control circuit 70 so as to effect selective energization of the heating unit 30 so that the bottom wall of the supported cooking vessel is maintained at a temperature in the approximate range 230 F.-425 F., the rotary controller 155B being enabled and selectively operative to effect the F. modification of the temperature band within the fry temperature range noted fundamentally established by the pushbutton controller MA.

As previously explained, the foregoing fixed heating rate controls and selective temperature controls are selectively set by the selective operations of the pushbutton switch 19, the pushbutton controller MA and the rotary controller 19B, independently of the cooking position of the heating unit 30 in the combination appliance l; whereby these selective heating and temperature controls may be achieved either in deep-well cooking operations or in surface-unit cooking operations in the cornbination appliance 14.

As indicated in Figs. 2, 5 and 6, the flexible power cable Si) and the flexible control cable S3 extending through the tube 39 respectively to the power terminals 36 and to the control terminals 57 accommodate the required movements of the heating unit 3d in the receptacle 24 between its respective lower deep-well cooking position and upper surface-unit cooking position; and moreover, the fiexible control cable 83 also accommodates the movements of the temperature sensing unit lil between its lower and upper positions, and the consequent pivoting of the tube 4l respectively in response to placement and to removal of a cooking vessel upon the heating platform of the heating clement 35, when the heating unit 3f) occupies either of its respective cooking positions. Finally, the flexible wiring 58 accommodates the universal movements of the temperature sensing button 45 upon the upper end of the arm 43 of the tube 4i.

ln view of the foregoing, it is apparent that there has been provided an improved cooking system employing a combination deep-well and surface-unit cooking appliance, wherein complete flexibility of selective heating and temperature control is preserved in the respective coo-king operations thereof.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall Within the true spirit and scope of the invention.

What is claimed is:

l. in a combination deep-well and surface-unit cooking appliance including an opstanding receptacle provided with lower and upper supports, and a hotplate provided with an electric heating unit and arranged in said receptacle and movable between a deep-well cooking position carried by said lower support and a surface-unit cooking position carried by said upper support and defining a heating platform adapted to support a cooking vessel in good heat-exchange relation therewith in the respective cooking positions thereof; the combination comprising a temperature sensing unit provided with a temperaturecontrolled element, resilient means mounting said temperature sensing unit upon said hotplate and in a substantially central opening provided therethrough, whereby said temperature sensing unit is movable both with said hotplate and with respect thereto, said resilient means biasing said temperature sensing unit into an upper position in which the top thereof is disposed somewhat above the plane of said heating platform and accommodating movement of said temperature sensing unit into a lower position in which the top thereof is disposed substantially in the plane of said heating platform, said temperature sensing unit being moved into its respective lower and upper positions in response to respective placement and removal of a cooking vessel with respect to said heating vplatforiri so that said temperature sensing -unit urged into good heat-exchange engagement With the bot-telnet a cooking vessel supported upon :said heating platform when said hotplate occupies -either 'of its vcooking positions, a exible power Iconnector extending through an opening in said receptacle and terminated by said electrlc heating Vunit and accommodating the movements 4of said hotplate between its respective Lcooking-positions, and a ex'ible control connector also'extending Vthrough 'an vopening `in said receptacle and terminated by said temperaturecontr'olled element `and accommodating both the movements of said hotplate between its respective cooking `positions and the movements of said temperature lsensing unit between its respective upper and -lower positions.

2. In a combination ldeep-well 'and 'surface-unit 'cooking appliance including an upstanding receptacle :provided with lower and uppersupports, and la hotplate provided with an electric heating unit an'd arranged in said recep- -tacle and movable between a ydeep-well cooking position carried by said lower support and a Lsurface-unitcooking position carried Iby said upper support and-defining 'a heating platform adapted to support a cooking fvessel in good heat-exchange relation therewith in `the respective cooking positions thereof; `the 'combination comprising -'a temperature sensing unit .provided with sa temperamrecontrolled element, resilient `means mounting fsaid Vternperature sensing unit upon said xhotplate fand'in a substantially central 'opening provided therethrough, 'whereby said temperature sensing uni't is 'movable both with said hotplate and `with respect thereto, said resilient Vmeans iasing said temperature sensing unit into ranupper position in which the top 'thereof is disposed somewhat above Ithe plane of said heating platform and accommodating movement of said temperature sensing unit into aflower position yin which `the top thereof is I.disposed substantially in the plane of said heating platform, 'said vtemperature sensing vunit being moved into its I'respective lower :and upper positions yin response 4to respective .placement "and removal of a cooking vessel with respect to saidlheating platform so that said temperature sensinglunit fis urged into ygood :heat-exchange engagement with e'the bottom 'of a cooking vessel `supported upon f'said'fheati'ng platform when said hotplate occupies l'either l'of y(its 'cooking vp'ositions, a tubular guard :member .carried by 'said l'iotpi'late and extending throughan upstanding Slot provided insaid receptacle `and movable with said .hotplate 'between its `respective cooking :'positions, 'a `flexible power connector extending I through said t guard member'and ft'ermin'atedby said electric heating unit and `accomrnodating vthe movements of said hotplate between its respective-cooking 'positions, and a flexible :control 'connector-also V'eiitruding through said guard member 'and-terminated'bysid-temperature-controlled element fand 'accommodating l:both lthe movements lof vsaid fhotpla'te *between its respective l cook- :ing :positions and the movements of `said `'temperature 4 :sensing unit between its lrespective upper .and lower positions.

3. lnfa ccmbinationdeep-Well and sufaee-unit cookin'g appliance `-inluding San opstanding freceptacle 'provided Vwith lower Aand Iupper supports, 1 and a ihotplate -p'rovided with anelectric heatingiunitand 4arranged inisaid lreceptacle and movable 'between a deep-wellfcokingfpositi'on carried by -said 4lower support and a vsurface-unit cooking position carriedby 'saidupper 'support 'and 'defining a heating platform ladapted to f support a "cooking Vessel Ein 'good `heat-exch'ange relation therewith in lthe 'respective cooking positions "thereof; the combination comprising a temperature sensing unit provided with a thermistor, resilient means mounting said temperature sensing unit upon said hotplateland in a substantiallyvcensd heating platform and accommodating 1movement fof said temperature sensing unit into a lower ,posi-tion in which :the top thereof is ydisposed substantially in the plane yof said heating platform, -said `temperature sensi-ng -unit being moved into its respective lower and vupper ,po- 'sitions response to respective placement and removal of a cooking `vessel wit-h respect -to said heating platform so that said temperature sensing unit is urged into `good heat-exchange yengagement with the bottom of a cooking vessel supported upon .said heating platform when said hotplate occupies eitherof its cooking positions, a dexible power connector extending through an opening vin said receptacle and terminated by said electric heating unit and accommodating the movements of said hotplate between .its respective cooking positions, and a cxible control connector also extending through an :opening in .said receptacle yand terminated by said thermistor and accommodating both the vmovements -of said hotplate be- .tween its respective .cooking gposition-s Pand lthe ,movements of said .temperature .sensing unit` between lits `respective upper and lower positions. n

4. In 1a Vcooking appliance, Ya hotplate ,provided with :an electric heating unit and defining la heating platform .adapted vto support a cooking vessel `in good heat-.exchange :relaticntherewith Aand having a substantial central opening therethrough, .an arm arranged below said heating unit and ,provided -with an outwardly directed youter .end Iand :an upwardly directed `inner end terminating below said .central opening, lfirst vmeans mounting .the louter end of said arm upon sa'id hotplate for pivoted movements .with respect thereto, a temperature sensing yunit provided with .a .temperature-controlled element and arranged in said central opening, second means .mounting said temperature sensing .unit Aupon lthe inner .end of said a'rinlfor universal movements with respect thereto, said r'stmounting .means .accommodating :pivotal movement ofsa'id .arm between alower ,position in whichrthe top 'f said temperature sensing unit is disposed substantially in the plane of said heating. ,platformfand an upper {positionin which ,the top of said temperature sensing unit is disposed .somewhat above the plane of said heating platform, biasing means for urging said arm upwardly from its lower .position into its :upper position, said .arm being .moved :against .said biasing means `from its upper ,positioninto its lower position in response t0 `placement ,of la cooking vessel upon said Aheating platform,said.biasinglmeansetecting the returntof said arm froin .its .lowert position into its Vupper ,position in vresponse .to removal .of .a .cooking .vessel from 4said heating platform, .stop means .for `limiting upward-movement of said arm beyond its upper position, said second vmounting means accommodatingany required movements between vsaid temperaturesensing ,unitandthefinner-end of said arm to adjust the .top .of said .temperature sensing unit into Agood heat-.exchange engagement with the ;bottom,of a cooking vessel supported Aupon said heating lplatform, and a flexible controlfconnector extending-from said temperature-controlled .element to the .exterior and accommodating both the movementsoffsaidarm between its upper-and lower ,positions .and the movements of `said temperature sensingunit with respect totheinner end of said arm.

f5. The cooking Iappliance set forthdn claim 4, whereinsid arr'nfistf vtubular structureand said exible-contrl connector-.extends.through said tubular arm between 'said vte'mperature-controlled elementandthe exterior.

y6. The cooking appliance-settorth inclaim 4, wherein said second mounting.meansconsists.essentially of cooperating'ball and .socketpartsyone-of said parts being carried `on the innerend of :said:arm,-and the-other of .said,parts being carried onfthe bottom of said temperaturesensingunit. -7. :Int-a cookingvappliance, an felectric'heating unit includingfamlurality'of spacedsapart substantially spiral Vturns defining fa :cheating 1p1atform adapted Ato support a cooking vessel in good heat-exchange relation therewith, the innermost turn of said heating unit also defining a substantially central opening therethrough, open supporting structure carrying said heating unit, an arm arranged below said heating unit and provided with an outwardly directed outer end and an upwardly directed inner end terminating below said central opening, first means mounting the outer end of said arm upon said supporting structure for pivotal movements with respect thereto, a temperature sensing unit provided with a temperature-controlled element and arranged in said central opening, second means mounting said temperature sensing unit upon the inner end of said arm for universal movements with respect thereto, said rst mounting means accommodating pivotal movement of said arm between a lower position in which the top of said temperature sensing unit is disposed substantially in the plane of said heating platform and an upper position in which the top of said temperature sensing unit is disposed somewhat above the plane of said heating platform, biasing means acting between said arm and said supporting structure for urging said arm upwardly from its lower position into its upper position, said arm being moved against said biasing means from its upper position into its lower position in response to placement of a cooking vessel upon said heating platform, said biasing means effecting the return of said arm from its lower position into its upper position in response to removal of a cooking vessel from said heating platform, stop means acting between said arm and said supporting structure for limiting upward movement of said arm beyond its upper position, said second mounting means accommodating any required movements between said temperature sensing unit and the inner end of -said arm to adjust the top of said temperature sensing unit into good heat-exchange engagement with the bottom of a cooking vessel supported upon said heating platform, and a flexible control connector extending from said temperamro-controlled element to the exterior and accommodating both the movements of said arm between its upper and lower positions and the movements of said temperature :sensing unit w-ith respect to the inner end of said arm.

8. In a cooking appliance, a hotplate provided with an electric heating unit and defining a heating platform adapted to support a -cooking vessel in good heat-exchange relation therewith and having a substantially central opening therethrough, an arm arranged below said heating unit and provided with an outwardly directed outer end and an upwardly directed inner end terminating below said central opening, rst means mounting the outer end of said arm upon said hotplate for pivotal movements with respect thereto, a temperature sensing unit provided with a thermostor and arranged in said lcentral opening, second means mounting said temperature sensing unit upon the inner end of said arm for universal movements with respect thereto, said first mounting means accommodating pivotal movement of said arm between a lower position in which the top of said temperature sensing unit is disposed substantially in the plane of said heating platform and an upper position in which the top of said temperature sensing unit is disposed somewhat above the plane of said heating platform, biasing means for urging said arm upwardly from its lower position into its upper position, said arm being moved against said biasing means from its upper position into its lower position in response to placement of a cooking vessel upon said heating platform, said biasing means effecting the return of said arm from its lower position into its upper position in response to removal of a cooking vessel from said heating platform, stop means for limiting upward movement of said arm beyond its upper position, said second mounting means accommodating any required movements between said temperature sensing unit and the inner end of said arm to adjust the top of said temperature sensing unit into good heat-exchange engagement with the bottom of a cooking vessel supported upon said heating platform, said arm being of tubular structure, and a iiexible control connector extending through said tubular arm from said thermistor to the exterior and accommodating both the movements of said tubular arm between its upper and lower positions and the movements of said temperature sensing unit with respect to the inner end of said arm.

9. In a combination deep-well and surface unit cooking appliance including an upstanding receptacle provided with lower and upper supports, and a hotplate provided with an electric heating unit and arranged in said receptacle and Imovable between a deep-well cooking position carried by said lower support and a surface-unit cooking position carried by said upper support and deiining a heating platform adapted to support a cooking vessel in good heat-exchange relation therewith in the respective cooking positions thereof; the combination comprising an arm arranged below said heating unit and provided with an outwardly directed outer end and an upwardly directed inner end terminating below said central opening, rst means mounting the outer end of said arm upon said hotplate for pivotal movements with respect thereto, a temperature sensing unit provided with a temperature-controlled element and arranged in said central opening, second means mounting said temperature sensing unit upon the inner end of said arm for universal movements with respect thereto, said first mounting accommodating pivotal movement of said arm between a lower position in which the top of said temperature sensing unit is disposed substantially in the plane of said heating platform and an upper position in which the top of said temperature sensing unit is disposed somewhat above the plane of said heating platform, biasing means for urging said arm upwardly from its lower position into its upper position, said arm being moved against said biasing means from its upper position into its lower position in response to placement of a cooking vessel upon said heating platform when said hotplate occupies either of its cooking positions, said biasing means effecting the return of said arm from its lower position into its upper position in response to removal of a cooking vessel from said heating platform when said hotplate occupies either of its cooking positions, stop means for limiting upward movement of said arm beyond its upper position, said second mounting means accommodating any required movements between said temperature sensing unit and the inner end of said arm to adjust the top of said temperature sensing unit into good heat-exchange engagement with the bottom of a cooking vessel supported upon said heating platform when said hotplate occupies either of its cooking positions, a flexible power connector extending through an opening in said receptacle and terminated by said electric heating unit and accommodating the movements of said hotplate between its respective cooking positions, and a exible control connector also extending through an opening in said receptacle and terminated by said temperature-controlled element and accommodating both the movements of said hotplate between its respective cooking positions and the movements of said temperature sensing unit between its respective upper and lower positions as well as the movements of said temperature sensing unit with respect to the inner end of said arm.

l0. In an electric range, a combination deep-well and surface-unit appliance including a heating unit selectively movable into corresponding cooking positions, said heating unit being adapted to support a cooking vessel in good heat-exchange relation therewith in the respective cooking positions thereof and including a temperature sensing unit adapted to sense the temperature of the bottom of the supported cooking vessel, a source of electric power, automatic control equipment, a supply connection extending between said automatic control equipment and said heating unit, a iiexible control connector extending between said temperature sensing unit and said automatic control equipment and accommodating the movements of said heating unit between its respective cooking positions, a manually operable circuit controller having a plurality of control positions and an automatic position and an oit position, said circuit controller being operative into respective ones of its plurality of control positions to complete a corresponding plurality of diifen ent heating connections directly between said source and said heating unit independently of said automatic control equipment, said circuit controller being operative into its automatic position to complete a feed connection from said source to said automatic control equipment, said circuit controller being operative into its olf position to interrupt both each of said heating connections and said feed connection, said automatic control equipment being operative in response to the completion of said feed connection thereto selectively to complete said supply connection, and a manually operable temperature controller selectively settable in accordance with the desired ternperature of a cooking vessel supported by said heating unit, said automatic control equipment being governed jointly by said temperature sensing unit and by said temperature controller in its operation selectively to complete said supply connection so as to maintain the preset desired temperature of the cooking vessel supported by said heating unit, said heating connections and said supply connection including a common flexible power cable accommodating the movements of said heating unit be- 10 tween its respective cooking positions.

References Cited in the le of this patent UNITED STATES PATENTS 15 2,430,196 Vaughan Nov. 4, 1947 2,519,051 Kirk Aug. 15, 1950 2,534,097 Akeley Dec. 12, 1950 

